I've finally found a well-sorted affordable 03 XJR- I am going out to look at it next week- the issue that concerns me is that it has 140K miles- one owner, well maintained, cam tensioners addressed, new shocks and struts, all mechanicals and electronics working, interior immaculate. routine maintenance done by Jaguar, never seen salt or snow - it's a car purchased in Nevada but has lived most it's life in central Oregon. any thoughts about other things to look for or forecasts about the future? Or?

As long as it's been properly maintained, the mileage is of no concern (at least in my opinion.) Maybe if we were talking about a car that had 200k or more, but that's not the case here. I say go for it

Glad to see you found one here in Illinois.. All the '03's that I've found have been out of state

03 shouldn't have had tensioner issues.

The MB transmissions normally last way past 150k ... it's a question of use. If it's your only car and you are driving 60 miles each day ... may be an issue. Sunday car .. no problem.

Mine's at 148k, I drive mine every day that far or farther on some. Probably not quite as maintained as the one you're looking at, if I'm completely honest, but I'm working on it. And I have no hesitation every day of getting in and taking off. At 135k, I drove it almost four thousand miles on a road trip with zero issues (other than my own doing). If it's well maintained, I would have no worries or second thoughts about the mileage.

I know an XJR with regular services on near 300k miles. Mainly motorway which helps. That car is faultless, but it needed a new throttlebody at around 150k and a supercharger not long after, the last thing was the ABS pump module, this needed the power pickups resoldering. Other than that, all good. All 3 of these issues are covered in depth in this forum and are known common faults, with various fixes and answers.
Bushes and bearings wear out and start to make a noise to let you know, very helpful of them. 03's shouldn't need a tensioner update as they came from the factory already fitted, if there's an invoice for the work, avoid that garage!
If the battery is more than 4 years old change it so you dont get puzzling/worrying phantom fault lights, these cars sensitive to Vdrop.

"new shocks and struts". The X308 doesn't have struts. It has double wishbone suspension with separate shock absorbers.

The fuel pumps seem to fail every 50K miles, so I would check when they were done last and expect to do them before another 50K is up.

The transmission will be screaming for a service. I changed my fluid at 135K, and it was last done at 50K, so that's 80K on the fluid and filter. It was in a disgusting state - 1/2" of black sludge at the bottom of the pan.

At that mileage I would expect the front and rear suspensions to be due for a refresh, with new ball joints, bushings, and so on.

Like everyone seems to be saying, the mileage is a non-issue if the car has been taken car of. My 03 XJR was not nearly as well taken car of as my 2001 XJ8 was, but ironically I find myself trusting it a lot more. I serviced the transmission, like Mark recommended, and the car just seems robust.

I think, to use a real estate term, the 03 XJR has got "good bones". It's a very solid car underneath and if the maintenance items are addressed the darn things will last a long time.

I say a lot of this based on research since this is my first XJR and I've had it less than two months, but it's my 3rd Jaguar.